The present invention pertains to hand stamps. More particularly, the present invention pertains to hand stamps that are compact and include microporous marking structures.
Microporous marking structures for use with hand stamps are typically made of a polymeric material, or other open cell compositions, such as specially formulated foam, and resin, such as thermoplastic resin, which combine to form a slab-like structure including a large quantity of microscopic pores. The microporous structure may be impregnated with ink or other suitable marking fluid, which fill many of the microscopic pores.
Hand stamps having microporous marking structures are commercially known as pre-inked hand stamps as they can be used to create numerous impressions without requiring a user to introduce additional ink into the marking structure. This is possible due to the microscopic size of the pores, which allow the ink initially retained therein to escape at a controlled rate.
One brand of high quality pre-inked hand stamps is manufactured and sold by MandR Marking Systems, Inc. of Piscataway, N.J. under the trademark ROYAL MARK. These pre-inked marking structures are made from ROYAL MARK brand gel which comprises a mixture of thermoplastic resin and ink. This mixture is also known as pre-mix used for manufacturing microporous marking structures.
Various methods of manufacturing such microporous marking structures exist. When microporous structures for use with currently available ROYAL MARK pre-inked hand stamps are manufactured, the pre-mix, which includes a desired quantity of ink, is poured into a mold. The mold is then heated in a vulcanizer at a predetermined pressure and temperature for a selected period of time. When this procedure is completed, the marking structure has the form of a microporous slab and may be removed from the mold. Typically, excess ink is then removed from the marking structure by a process known as stabilizing.
Another known method of manufacturing microporous marking structures contemplates initially forming a microporous structure without ink. Such microporous structures may be manufactured by sintering, salt-leaching or other methods. MandR Marking Systems also manufactures and sells this type of marking structures and associated hand stamps under the trademark OPTIMARK. This type of microporous structure is then impregnated with ink during a separate procedure which may require immersing of the microporous marking structure in an ink pool, subjecting the microporous marking structure and ink to a vacuum environment or other known methods. With this type of marking structure, it is also usually required to stabilize the structure (i.e., remove excess ink therefrom) prior to assembly on a hand stamp mount.
Regardless of whether the microporous marking structures have been manufactured from gel material, where ink is initially impregnated therein during the manufacturing process, or whether they are initially formed without ink, such microporous marking structures are secured to a platen of a hand stamp.
Hand stamps are typically operable between a rest position, where the marking structure is remote from a surface to be imprinted and a printing position, where the marking structure is in contact with a surface to be imprinted. Movement of the marking structure occurs upon depression of a handle or a case by a user of the hand stamp.
Because pre-inked hand stamps do not need a separate ink pad as a source of ink, the printing face of the marking structure is typically arranged parallel to the plane of a surface to be imprinted at all times. Thus, when the marking structure is in a rest position, it is spaced from and extends coplanar with the surface to be imprinted. As the printing surface of the marking structure is moved into its printing position, it continues to face the surface to be imprinted through contact with such surface.
High quality self-inking hand stamps are also sold by MandR Marking Systems, Inc. One well-known brand is marketed under the trademark IDEAL(copyright). Examples of IDEALS brand self-inking hand stamps are described in U.S. Pat. Nos. 5,649,485, 4,852,489 and 4,432,281.
The marking structures in self-inking hand stamps are typically made of rubber or the like and must be placed in contact with a source of ink, such as an internal ink pad, when the hand stamp is in a rest position. The ink pad may be permanently arranged within the hand stamp or may be removable therefrom, such as the ink pad disclosed in the ""485 patent.
Rubber marking structures used in self-inking hand stamps have a printing surface, which is typically arranged to face 180 degrees away from the surface to be imprinted when the hand stamp is in a rest position. When the hand stamp is depressed into a printing position, the marking structure may be moved along with a platen on which it is mounted through 180 degrees until it contacts the surface.
Thus, the movement of the marking structure in a pre-inked hand stamp is different from the movement of prior art marking structures in self-inking hand stamps. Pre-inked and self-inking hand stamps typically include a frame that is sized and shaped to accommodate a pre-inked marking structure that can easily move between rest and printing positions. The frame of prior art hand stamps must be large enough to enclose the width of associated marking structures. This is a shortcoming of prior art hand stamps as they are often larger than desired by the user.
Prior art hand stamps sometimes include one or more reinking ports. For example, reinking ports have been arranged on the platen of pre-inked hand stamps to permit a user to selectively apply ink or other marking fluid to the rear surface of a microporous marking structure secured to the platen. Reinking ports have also been used in prior art self-inking hand stamps on the rear surface of an inkwell so that a user can apply ink, or other marking fluid, to an associated ink pad.
However, one drawback of prior art hand stamps including reinking ports is that the reinking ports expose the ink-impregnated marking structure or ink pad to air and contaminants, thus contributing to contamination or premature drying out of the ink retained therein.
The present invention addresses the aforementioned shortcomings associated with prior art hand stamps. In one embodiment, a hand stamp comprises a compact hand stamp. The hand stamp may comprise a frame and a case arranged for slidable movement on the frame. A platen may be connected to the case and is movable therewith. A marking structure may be mounted on the platen. The marking structure may include a rear surface adjacent the platen and a front surface including a design thereon. The marking structure is movable with the platen between a rest position where the design is remote from a surface to be imprinted and a printing position where the design is in contact with the surface to be imprinted. Preferably, the marking structure is arranged at an angle of about 90 degrees with respect to the surface to be imprinted when it is in a rest position.
In a preferred embodiment, the marking structure may comprise a microporous material. Marking fluid may be impregnated into the microporous material. Thus, in a preferred embodiment, the hand stamp comprises a pre-inked hand stamp. In alternate embodiments, the hand stamp may comprise a self-inking hand stamp.
Preferably, the platen comprises a front surface, which faces the rear surface of the marking structure and a rear surface, which faces away from the marking structure. At least one reinking port preferably extends through the front and rear surfaces of the platen to permit marking fluid to be applied to the rear surface of the marking structure and to thus be absorbed therein.
In another preferred embodiment, the at least one reinking port may comprise a plurality of reinking ports. In a particular preferred embodiment, the plurality of reinking ports may comprise two reinking ports.
The hand stamp may also comprise a cover member arranged on the rear surface of the platen. The cover member is preferably movable between a sealed position where it is arranged adjacent to the at least one reinking port and an open position where it is at least partially remote from the at least one reinking port whereby marking fluid can be applied to the rear surface of the marking structure. It is also preferable for the cover to be mounted for slidable movement on the rear surface of the platen. Thus, the cover may be secured on the platen in close proximity to the marking structure.
The hand stamp may also comprise at least one spring arranged between the case and the frame. The at least one spring is operative to bias the case away from the frame, such that the marking structure is remote from the surface to be imprinted when in its rest position.
The hand stamp may also comprise restricting means for restricting movement of the platen and the marking structure thereon through a range of about 90 degrees between the rest position and the printing position. The restricting means may comprise cooperating features of the frame and the case. The platen may further comprise a frame arranged on the rear surface thereof adjacent to the at least one reinking port. In this preferred embodiment, the cover member is preferably arranged within the platen frame when in its sealed position.
In another preferred embodiment, the cover member may comprise a plurality of panels mounted on the rear surface of the platen and is movable between a sealed position where the plurality of panels are arranged adjacent to corresponding ones of the plurality of reinking ports and an open position where the plurality of panels are at least partially remote from the plurality of reinking ports whereby marking fluid can be applied to the rear surface of the marking structure.
Various advantages are obtained by using the hand stamp of the present invention. For example, it may be compact due to the structure and arrangement of the platen, the case and the frame. Further, the structure and arrangement of the cover member on the platen may serve to prolong the life of the associated marking structure and may protect it against contaminants such as dust or the like. The arrangement of the cover member also contributes to the compact nature of the present hand stamp.
Additional advantages and features of the present invention will be more fully understood in view of the following detailed description of the preferred embodiments and corresponding drawings.